CURLOPT_LOCALPORT

Section: curl_easy_setopt options (3)
Updated: November 04, 2020
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NAME

CURLOPT_LOCALPORT - set local port number to use for socket

SYNOPSIS

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_LOCALPORT, long port);

DESCRIPTION

Pass a long. This sets the local port number of the socket used for the connection. This can be used in combination with CURLOPT_INTERFACE(3) and you are recommended to use CURLOPT_LOCALPORTRANGE(3) as well when this option is set. Valid port numbers are 1 - 65535.

DEFAULT

0, disabled - use whatever the system thinks is fine

PROTOCOLS

All

EXAMPLE

CURL *curl = curl_easy_init();
if(curl) {
  curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/foo.bin");
  curl_easy_setopt(curl, CURLOPT_LOCALPORT, 49152L);
  /* and try 20 more ports following that */
  curl_easy_setopt(curl, CURLOPT_LOCALPORTRANGE, 20L);
  ret = curl_easy_perform(curl);
  curl_easy_cleanup(curl);
}

AVAILABILITY

Added in 7.15.2

RETURN VALUE

Returns CURLE_OK